Motion artifact reduction of diffusion-weighted MRI of the liver: Use of velocity-compensated diffusion gradients combined with tetrahedral gradients

• Published in: Journal of magnetic resonance imaging 2013-01, Vol.37 (1), p.172-178
• Main Authors: Ozaki, Masanori, Inoue, Yusuke, Miyati, Tosiaki, Hata, Hirohumi, Mizukami, Sinya, Komi, Shotaro, Matsunaga, Keiji, Woodhams, Reiko
• Format: Article
• Language: English
• Subjects: Adult; apparent diffusion coefficient; cardiac motion; Diagnostic Imaging - methods; Diffusion; Diffusion Magnetic Resonance Imaging - methods; diffusion-weighted imaging; Echo-Planar Imaging - methods; Female; Humans; Image Processing, Computer-Assisted; liver; Liver - pathology; Magnetic resonance imaging; Male; Models, Statistical; Motion; Reproducibility of Results; Signal-To-Noise Ratio; velocity compensation
• ISSN: 1053-1807; 1522-2586
• DOI: 10.1002/jmri.23796

Purpose: To assess the effect of motion artifact reduction on the diffusion‐weighted magnetic resonance imaging (DWI‐MRI) of the liver, we compared velocity‐compensated DWI (VC‐DWI) and VC‐DWI combined with tetrahedral gradients (t‐VC‐DWI) to conventional DWI (c‐DWI) in the assessment of apparent diffusion coefficients (ADCs) of the liver. Materials and Methods: In 12 healthy volunteers, the liver was scanned with c‐DWI, VC‐DWI, and t‐VC‐DWI sequences. The signal‐to‐noise ratio (SNR) and ADC of the liver parenchyma were measured and compared among sequences. Results: The image quality was visually better for t‐VC‐DWI than for the others. The SNR for t‐VC‐DWI was significantly higher than that for VC‐DWI (P < 0.05) and comparable to that for c‐DWI. ADCs in both hepatic lobes were significantly lower for t‐VC‐DWI than for c‐DWI (P < 0.01). ADC in the left lobe was significantly lower for VC‐DWI than for c‐DWI (P < 0.01). Although ADC in the left lobe was significantly higher for c‐DWI (P < 0.01), no significant differences in ADCs were found between the right and left lobes for VC‐DWI and t‐VC‐DWI. Conclusion: The use of a t‐VC‐DWI sequence enables us to correct ADCs of the liver for artificial elevation due to cardiac motion, with preserved SNR. J. Magn. Reson. Imaging 2013;37:172–178. © 2012 Wiley Periodicals, Inc.